INTERACTIVE TIMELINE: Boston Marathon makes history for 122 years

For 120 years, runners have pounded the pavement to complete the Boston Marathon. On April 17, more than 30,000 runners will take to the course for the 121st race.

Check out this timeline of some of the historic moments during the run's history including women being allowed to run, the start of the wheelchair competition and moving the starting line to Hopkinton.